Hardware knowledge: how to choose the type and type of imported bearings

When choosing imported bearings, we should choose whether the imported bearings meet the scope of our machinery according to the size, specifications, and speed of the imported bearings. Here is a simple analysis:

First of all, the size limit.

Usually, the space in which imported bearings can be installed is limited. In most cases, the shaft diameter (or imported bearing inner diameter) is based on mechanical design or other design constraints. Therefore, the choice of imported bearing type and size is determined according to the inner diameter of the imported bearing. Therefore, the main size tables of standard imported bearings are compiled according to the international standard inner diameter size.

There are many sizes of standard imported bearings. It is best to use standard imported bearings when designing mechanical devices. , But some non-standard imported bearings are not available in mainland China, and sometimes the futures will be long. Therefore, the time cost and the cost of later replacement should be considered when selecting imported bearings.) The load of imported bearings is imposed on imported bearings. The nature, size, and direction of the load are changeable. Usually, the rated basic load is shown on the dimension table. However, axial load and radial load are also important factors in choosing suitable imported bearings. When the size of the ball and needle roller bearings are the same, the imported needle roller bearings usually have a higher load capacity and can withstand greater vibration and shock loads.

Next is the speed.

The allowable speed is determined according to the imported bearing type, size, accuracy, cage type, load, lubrication method, and cooling method. The table of imported bearings lists the allowable speed of standard precision imported bearings under oil lubrication and grease lubrication. Generally, deep groove ball bearings, self-aligning ball bearings and cylindrical roller bearings are suitable for high-speed operation.

Again, the tolerance of imported bearings.

The dimensional accuracy and rotation accuracy of imported bearings are based on ISO and JIS standards. For machinery requiring high precision and high-speed operation, it is recommended to use imported bearings with accuracy of 5 or above. Deep groove ball bearings, radial thrust ball bearings or cylindrical roller bearings are suitable for machinery with high operating accuracy. Rigidity, when the contact surface of the rolling element and raceway of the imported bearing is compressed, it will produce elastic deformation. Some machines need to minimize elastic deformation. Imported roller bearings produce smaller elastic deformations than imported ball bearings.

In addition, in some cases imported bearings need to be preloaded to increase rigidity. This program is usually used for deep groove ball bearings, radial thrust ball bearings and tapered roller bearings to offset the inner and outer rings, shaft bending, shaft or imported bearing housing tolerance changes, and matching errors will lead to eccentricity of the inner and outer rings. In order to prevent the eccentric angle from being too large, self-aligning ball bearings, self-aligning roller bearings, or self-aligning bearing seats are better choices. The voice frequency and torque, and rolling bearings are manufactured according to high-precision standards, so the voice and torque are small. Deep groove ball bearings and cylindrical roller bearings are suitable for occasions with special requirements for low noise and low torque.

Installation and disassembly, some applications require frequent disassembly and installation to ensure regular inspection and maintenance. Imported bearings whose inner and outer rings can be installed separately, such as cylindrical bearings, needle roller bearings, and tapered bearings are very suitable for this occasion. The tapered hole type self-aligning ball bearing and self-aligning roller bearing also simplify the installation procedure with the help of the sleeve.